K. Dehmelt
A5104470371- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Particle Detector Development and Performance
- Radiation Detection and Scintillator Technologies
- Dark Matter and Cosmic Phenomena
- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Nuclear reactor physics and engineering
- Photocathodes and Microchannel Plates
- Cosmology and Gravitation Theories
- Superconducting Materials and Applications
- Atomic and Subatomic Physics Research
- Nuclear physics research studies
- Stochastic processes and statistical mechanics
- CCD and CMOS Imaging Sensors
- Neutrino Physics Research
- Distributed and Parallel Computing Systems
- Advanced Data Storage Technologies
- Radiation Therapy and Dosimetry
- Medical Imaging Techniques and Applications
- Statistical Methods and Bayesian Inference
- Nuclear Physics and Applications
- International Science and Diplomacy
- Markov Chains and Monte Carlo Methods
Stony Brook University
2015-2024
Thomas Jefferson National Accelerator Facility
2022-2024
Florida Institute of Technology
2011-2024
Bhabha Atomic Research Centre
2018-2024
Banaras Hindu University
2018-2024
Augustana University
2018-2024
State University of New York
2016-2024
Charles University
2018-2023
Abilene Christian University
2018-2023
PHENIX laboratory
2019-2023
The PHENIX experiment at the BNL Relativistic Heavy Ion Collider (RHIC) has measured electrons with $0.3<{p}_{T}<9\text{ }\text{ }\mathrm{GeV}/c$ midrapidity ($|y|<0.35$) from heavy-flavor (charm and bottom) decays in $\mathrm{Au}+\mathrm{Au}$ collisions $\sqrt{{s}_{\mathrm{NN}}}=200\text{ }\mathrm{GeV}$. nuclear modification factor ${R}_{\mathrm{AA}}$ relative to $p+p$ shows a strong suppression central collisions, indicating substantial energy loss of heavy quarks medium produced RHIC...
The production of low mass e+e- pairs for m_{e+e-} < 300 MeV/c^2 and 1 p_T <5 GeV/c is measured in p+p Au+Au collisions at sqrt(s_NN)=200 GeV. Enhanced yield above hadronic sources observed. Treating the excess as internal conversions, invariant direct photons deduced. In central collisions, photon over exponential transverse momentum, with inverse slope T = 221 +/- 19 (stat) (syst) MeV. Hydrodynamical models initial temperatures ranging from 300--600 MeV times ~ 0.6 - 0.15 fm/c after...
The PHENIX experiment at the BNL Relativistic Heavy Ion Collider (RHIC)has measured $J/\ensuremath{\psi}$ production for rapidities $\ensuremath{-}2.2<y<2.2$ in $\mathrm{Au}+\mathrm{Au}$ collisions $\sqrt{{s}_{NN}}=200\text{ }\text{ }\mathrm{GeV}$. invariant yield and nuclear modification factor ${R}_{AA}$ as a function of centrality,transverse momentum, rapidity are reported. A suppression relative to binary collision scaling proton-protonreaction yields is observed. Models which describe...
Differential measurements of elliptic flow (${v}_{2}$) for $\mathrm{Au}+\mathrm{Au}$ and $\mathrm{Cu}+\mathrm{Cu}$ collisions at $\sqrt{{s}_{\mathrm{NN}}}=200\text{ }\text{ }\mathrm{GeV}$ are used to test validate predictions from perfect fluid hydrodynamics scaling ${v}_{2}$ with eccentricity, system size, transverse kinetic energy (${\mathrm{KE}}_{T}$). For ${\mathrm{KE}}_{T}\ensuremath{\equiv}{m}_{T}\ensuremath{-}m$ up $\ensuremath{\sim}1\text{ the is compatible hydrodynamic expansion a...
Azimuthal angle ($\ensuremath{\Delta}\ensuremath{\phi}$) correlations are presented for a broad range of transverse momentum ($0.4<{p}_{T}<10$ GeV/$c$) and centrality (0--92%) selections charged hadrons from dijets in Au+Au collisions at $\sqrt{{s}_{\mathit{NN}}}=200$ GeV. With increasing ${p}_{T}$, the away-side $\ensuremath{\Delta}\ensuremath{\phi}$ distribution evolves relatively flat shape to concave shape, then convex shape. Comparisons with $p+p$ data suggest that can be divided into...
For Au + collisions at 200 GeV, we measure neutral pion production with good statistics for transverse momentum, pT, up to 20 GeV/c. A fivefold suppression is found, which essentially constant 5 < pT Experimental uncertainties are small enough constrain any model-dependent parametrization the transport coefficient of medium, e.g., q in parton quenching model. The spectral shape similar all collision classes, and does not saturate collisions.
PHENIX has measured the e^+e^- pair continuum in sqrt(s_NN)=200 GeV Au+Au and p+p collisions over a wide range of mass transverse momenta. The yield is compared to expectations from hadronic sources, based on measurements. In intermediate region, between masses phi J/psi meson, consistent with correlated c^bar-c production, though other mechanisms are not ruled out. low region (below phi) inclusive spectrum well described by known contributions light meson decays. contrast, minimum bias this...
Transverse momentum spectra of electrons (${p}_{T}^{e}$) from semileptonic weak decays heavy-flavor mesons in the range $0.3<{p}_{T}^{e}<9.0$ GeV/$c$ have been measured at midrapidity ($|y|<0.35$) by PHENIX experiment Relativistic Heavy Ion Collider $p+p$ and $\mathrm{Au}+\mathrm{Au}$ collisions $\sqrt{{s}_{\mathrm{NN}}}=200$ GeV. In addition, azimuthal anisotropy parameter ${v}_{2}$ has for $0.3<{p}_{T}^{e}<5.0$ collisions. The substantial modification ${p}_{T}^{e}$ compared with as well...
The PHENIX experiment at the Relativistic Heavy Ion Collider has measured invariant differential cross section for production of ${K}_{S}^{0}$, $\ensuremath{\omega}$, ${\ensuremath{\eta}}^{\ensuremath{'}}$, and $\ensuremath{\phi}$ mesons in $p+p$ collisions $\sqrt{s}=200\text{ }\text{ }\mathrm{GeV}$. Measurements $\ensuremath{\omega}$ different decay channels give consistent results. New results are agreement with previously published data extend ${p}_{T}$ coverage. spectral shapes all...
The momentum distribution of electrons from decays heavy flavor (charm and bottom) for midrapidity |y|<0.35 in p+p collisions at s=200 GeV has been measured by the PHENIX experiment BNL Relativistic Heavy Ion Collider over transverse range 0.3<pT<9 GeV/c. Two independent methods have used to determine heavy-flavor yields, results are good agreement with each other. A fixed-order-plus-next-to-leading-log perturbative QCD calculation agrees data within theoretical experimental uncertainties,...
Transverse momentum distributions and yields for ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$, ${K}^{\ifmmode\pm\else\textpm\fi{}}$, $p$, $\mathrm{p\ifmmode \bar{}\else \={}\fi{}}$ in $p+p$ collisions at $\sqrt{s}$ $=$ 200 62.4 GeV midrapidity are measured by the PHENIX experiment Relativistic Heavy Ion Collider (RHIC). These data provide important baseline spectra comparisons with identified particle heavy ion RHIC. We present inverse slope parameter ${T}_{\mathrm{inv}}$, mean...
The PHENIX experiment presents results from the Relativistic Heavy Ion Collider 2005 run with polarized proton collisions at $\sqrt{s}=200\text{ }\text{ }\mathrm{GeV}$, for inclusive ${\ensuremath{\pi}}^{0}$ production midrapidity. Unpolarized cross section are given transverse momenta ${p}_{T}=0.5$ to $20\text{ }\mathrm{GeV}/c$, extending range of published data both lower and higher ${p}_{T}$. is described well ${p}_{T}<1\text{ }\mathrm{GeV}/c$ by an exponential in ${p}_{T}$, and,...
J/psi production in p+p collisions at square root s=200 GeV has been measured by the PHENIX experiment BNL Relativistic Heavy Ion Collider over a rapidity range of -2.2<y<2.2 and transverse momentum 0<pT<9 GeV/c. The size present data set allows detailed measurement both pT distributions is sufficient to constrain models. total cross section times branching ratio Bll sigma pp J/psi=178+/-3stat+/-53sys+/-18norm nb.
The PHENIX experiment at the Relativistic Heavy Ion Collider has measured 2nd and 3rd order Fourier coefficients of azimuthal distributions direct photons emitted midrapidity in Au$+$Au collisions $\sqrt{s_{_{NN}}}=200$ GeV for various collision centralities. Combining two different analysis techniques, results were obtained transverse momentum range $0.4
Single- and multi-photon events with missing energy are selected in 619/pb of data collected by the L3 detector at LEP centre-of-mass energies between 189GeV 209GeV. The cross sections process e^+e^- -> nu gamma (gamma) found to be agreement Standard Model expectations, number light neutrino species is determined, including lower data, N_nu = 2.98 +/- 0.05 0.04. Selection results also given form tables which can used test future models involving single- signatures LEP. These final states...
The absolute muon flux between 20 GeV and 3000 is measured with the L3 magnetic spectrometer for zenith angles ranging from 0 degree to 58 degree. Due large exposure of about 150 m2 sr d, excellent momentum resolution chambers, a precision 2.3 % at in vertical direction achieved. ratio positive negative muons studied 500 GeV, average charge found be 1.285 +- 0.003 (stat.) 0.019 (syst.).
Yields for J/psi production in Cu+Cu collisions at sqrt s_NN=200 GeV have been measured over the rapidity range |y|<2.2 and compared with results p+p Au+Au same energy. The data offer greatly improved precision existing small to intermediate numbers of participants, where quark-gluon plasma transition threshold is predicted lie. Cold nuclear matter estimates based on ad hoc fits d+Au describe up N_part approximately 50, corresponding a Bjorken energy density least 1.5 GeV/fm(3).
The PHENIX experiment has measured the suppression of semi-inclusive single high-transverse-momentum ${\ensuremath{\pi}}^{0}$'s in Au+Au collisions at $\sqrt{{s}_{\mathit{NN}}}=200$ GeV. present understanding this is terms energy loss parent (fragmenting) parton a dense color-charge medium. We have performed quantitative comparison between various energy-loss models and our experimental data. statistical point-to-point uncorrelated as well correlated systematic uncertainties are taken into...